Rotary testing apparatus



Se t. 7, 1965 s. H. VON FUCHS 0 ROTARY TESTING' APPARATUS Filed Jan. 25, 1962 2 Sheets-Sheet 1 INVENTOR. Stephen von Fuchs Sept. 7, 1965 k H. von FUCHS 0 ROTARY TESTING APPARATUS Filed Jan. 26 1962 2 Sheets-Sheet 2 FIG. 4

INVENTOR.

Stephen von Fuchs United States Patent O 3,204,450 ROTARY TESTING APPARATUS Stephen H. von Fuchs, Belmont, Mass. assignor t George H. von Fuchs, Belmont, Mass. Filed Jan. 26, 1962, Sei. N0. 169,061 7 Claims. (C1. 73-64) This invention relates to testing apparatus and is particularly concerned with testing apparatus of the bomb type which is rotated in a heating environment.

It is an object of the invention to provide improved means for accomplishing the aforesaid rotation.

Another object of the invention is to provide means for facilitating the assernbly of the testing apparatus and rotating means in a heating device.

Other objects and advantages of the present invention Will be apparent from the following description taken in conjunction with the accornpanying drawings in Which:

FIGURE 1 is an elevation of apparatus cornprising the invention, irrelevant parts being omitted and a portion being shown in section;

FIGURE 2 is a top plan view of the driving basket;

FIGURE 3 is a vertical sectional view on line 33 of FIGURE 2;

FIGURE 4 is a vertical sectional view of the testing bomb; and

FIGURE 5 is an end view of the drive plate on the bottorn of the testing bomb.

In FIGURE 1 of the drawings the testing bomb 1 is shown in the driving basket 2, the latter being supported in a bearing 3 by the rotatable shaft 4. The bearing 3 extends through the Wall of a tank or other vessel 6 adapted to contain a bath of hat liquid such as oil for heating the bomb l. Rotation of the shaft 4 is accornplished by a suitable chain or gear drive (not shown) operatively connected to the sprocket 7 which is fastened by suitable means such as a Set screw 8 to the portion of the shaft 4 that extends through the wall of the tank 6. As is shown, the longitudinal axis of the testing bomb 1 extends at a vertical angle With respect to a horizontal plane, the angle preferred being approximately 30.

The testing bomb 1 is shown in more detail in FIG- URE 4. It comprises a metal cup body 11 preferably cast in one piece or machined for a solid rod, the open end cf the cup having an outwardly projecting threaded flange 12. The cup body 11 is closed by a metal lid 13 that has a reduced portion 14 extending into the mouth of the cup 11 and with an annular groove 16 in which there is provided an O ring 17. The lid 13 also is provided with a central threaded orifice 18 in which there is mounted the reduced threaded end 19 of the tubular metal stem 21. An O ring seal 22 is provided in a groove at the inner end of the reduced ortion 19 of the stem.

The lid 13 is held in place on the cup body 11 by a tubular metal cap 23. The cap 23 is provided With internal threads 24 at one end which engages the threads on the flange 12 of the cup. At its other end the cap 23 has an internal annular flange 26 which engages the top of the lid 13 when the cap is screwed down on the body 11. Holes 27 are provided at spaced intervals around the periphery of the cap 23 adjacent the flange 26. These holes can be engaged by a spanner wrench for tightening or loosening the cap and also serve to drain ofl. oil or other liquid frorn the interior of the cap above the lid 13.

On the bottorn of the cup body 11 there is secured,

preferably by brazing, a metal drive plate 28. The plate 28 is provided With an axial centering hole 29 and a plurality of drive holes 30 equidistantly spaced in a ring that is concentric with the hole 29 but radially rernoved therefrorn.

FIGURES 2 and 3 show in detail the driving basket 2. This comprises a metal body 36 one end of which is axially elongated to forn1 a hub 37 having a bete 38 for the drive shaft 4, the shaft being secured in the hub by the sei: screw 39. At its inner end the bore 38 is enlarged to provide a cylindrical weil 41. Seated in the Weil 41 is a magnet 42 which has a base 43 snugly fitting the well and a plurality of upwardly extending poles 44 arranged in a ring with alternate poles being of opposite polarity. Within the ring formed by the poles is a non-rnagnetic metal plug 46 in Which is seated an outwardly projecting centen'ng pin 47. At its other end the body 36 is provided with a cavity which is circular in cross-section. The wall of the outer portion 48 of the cavity tapers inwardly, preferably at an angle of about 45, to a cylindrical inner ortion 49 which is preferably of just slightly larger diameter than the outside diameter of the drive plate 28. The cavity is concentric with the well 41, the magnet 42 and the centering pin 47. In the bottorn of the cylindrical cavity ortion 49 are a plurality of studs 51 the heads of which are munded. The studs are arranged equidistantly in a ring concentric with the weil 41 and centering pin 47. They are of such size and so spaced that when the testing bomb 1 is placed in the driving basket 2 with the centering pin 47 engaged in the centering hole 29 of the drive plate 28 the head 015 each stud will project into one of the drive holes 30 in the drive plate.

Projecting outwardly from the body 36 of the driving basket 2 are a plurality of inclined circulating vanes 52, preferably formed integrally With the body 36.

Testing bombs of the type shown in FIGURE 4 are nsed for a number of purposes. A major use is in the testing of oils for resistance to oxidation. In such testing the oil sarnple is placed in the cup body 11 of the bomb with, if desired, a suitable catalyst and the bomb is closed by the lid 13 and the cap 23 aided by the 0 ring sea1 17 The bomb is then filled with oxygen under pressure throngh the hollow stem 21 and a pressure gage (not shown) is connected at the upper end of the stem. The oil-containing bomb is then heated, preferably in a bath of hot oil or other suitable liquid, to a predetermined temperature while rotating it at an angle (as shown in FIGURE 1). The oxidation resistance of the oil can be measured by the t'une required to obtain a predetermined pressure drop Within the bomb. The pressure is reduced, of course, as the oxygen in the bomb combines With the oil.

In making oil oxidation tests of the type described many samples are run and it is necessary to quickly rernove a bomb frorn the bot oil bath at the cornpletion of a test and mount a fresh bomb in the rotating apparatus. Consequently a bomb holder and driving mechanism Which is simple in construction and convenient and positive in operation is desired. This has now been supplied by the present invention.

Referring to FIGURE 1, it will be seen that the bomb cup 11 fits easily but closely Within the cylindrical inner cavity portion 49 of the driving basket 2. lt is secnrely held in Position during rotation even in the angular position shown by the magnet 42 in the basket coacting with the steel drive plate 28 on the bottorn of the cup 11. The centering pin 47 in the driving basket enters the Center hole 29 of the driving plate 28 and ensures that the array of drive holes 30 in the plate and the array cf studs 51 in the basket are axially aligned. It Will be obvious that the number of drive holes must be equal to the number of studs 01' a multiple thereof. As shown, there are twice as many holes as studs and this ratio has been found conducive to easy and rapid mounting of bombs in the driving basket. Since the magnet 42 holds Patented Sept. 7, 1965 3 the plate 28 firmly the studs 51 are held firmly in the drive holes 30 so as to positively rotate the bomb.

As Will be evident from the foregoing, mounting a bomb in the basket 2 is very simple since the inclined Wall of the outer cavity portion 48 guides the base f the bomb into the cylindrical portion 49 of the cavity and the pointed end of the centering pin 47 easily enters the centering hole 29 of the drive plate. N0 prelirninary matching of drive holes 30 With studs 51 is required, it is only necessary to rotate the bomb in the basket, and the studs Will engage in the drive holes and be held there by the magnet 42. T0 remove the bomb frorn the basket it is merely necessary pull it outwardly With enough force to disengage the plate 28 from the magnet.

In carrying out oil oxidation tests it is important that the oil in the bomb be heated quickly to the test temperature and that this temperature be maintained accurately, usually within :O.1 C. This requires a bomb which has a high thermal conductivity to allow rapid heat transfer, efficient mixing and good control of the heating bath. Since copper and certain copper alloys have relatively high thermal conductivities and are easily forrned, they are preferred for forming the bomb cup and lid although other metals and alloys having relative- 1y high therrnal conductivies may be used. If desired, the cup and lid may be plated, as for example With chromium, to prevent corrosion. The cap 23 may be made of any desired metal, ordinary carbon steel being suitable, and may be plated to protect against corrosion if desired. The stern 21 is preferably formed of metal having a relatively 10W thermal conductivity to minirnize heat loss from the heating bath. Stainless steel has been found very suitable for this element. Where a non-magnetic metal is used in forming the bomb cup 11 -the drive plate 28 which must be formed of iron, steel or other ferromagnetic metal is preferably formed as a separate element and secured in suitable manner, as by silversoldering, brazing or welding, for example, to the bottom of the cup. In the event that a bomb cup is used which is formed of a ferromagnetic metal, the drive plate Can be an integral art of the cup bottom.

The driving basket 2 is formed of a non-magnetic metal, aluminum being prefened, as are also the plug 46 and centering pin 47. The plug and pin may, if desired, be integral. It may be noted here that the pin 47, the plug 46 and the magnet 42 are preferably pressed into their respective locations, set screws 0r other suitable known means may be used to retain them in place if desired 0r necessary. The studs 51 which drive the bomb are also non-magnetic and may be conveniently made of brass 01' bronze.

From the foregoing description it Will be evident that the present invention provides driving and mounting means for a rotary testing bomb that is highly eflicient and convenient to use. The bomb can be easily placed in the driving basket even when the latter is rotating and will be firmly seated and positively driven. 011 the other band, the bomb will not be damaged if held against rotation since the rounded heads of the studs 51 can slip out of the drive holes in the driving plate. Thus, it can also be removed readily with the basket rotating. The basket allows access of the heating liquid to substantially all cf the cylindrical surface cf. the bomb thus facilitating heating and the vanes 52 on the basket serve to circulate the heating liquid so that its temperature is uniform.

While the invention has been illustrated by a single embodirnent, it Will be understood that other embodiments of the principles thereof are possible and that various modifications thereof may be made without departing from said pn'nciples. Accordingly, it is intended that the invention should not be considered as limited to the construction shown and described, but should be construed as broadly as permitted by the appended claims.

I claim:

l. In testing apparatus -of the character described, the c0rnbination of a testing bomb and cooperative supporting and rotating means therefoi'; said means being rotatable and having a cylindrical cavity, a magnet at the bottom of said cavity and dn'ving means at the bottom of said cavity around said magnet; said bomb having a ferromagnetic driving plate fitting Within said cavity, said plate having means engagecl by said driving means for rotating said bomb and being rotatably disengageable from said driving means.

2. Apparatus as set forth in clairn 1 in which said driving means comprises a plurality of rounded head studs and said means engaged by said driving means comprises a plurality of holes into which the rounded heads of said studs project.

3. A supporting and rotating device for a rotary Iesting bomb comprising a body and means for connecting said body to a rotating member, said body having an axial well opening at its outer end into an enlarged cavity, a magnet secured in said Well With the poles thereof extending to the bottorn of said cavity, and a plurality of rounded head studs projecting outwardly from the bottom of said cavity, said studs being adapted to engage means on said bomb for rotating it and being rotatably disengageable from said bomb.

4. A device as set forth in claim 3 in which said studs are arranged equidistantly in a circle concentric With said magnet.

5. A device as set forth in clairn 3 in which the Wall of the outer ortion of said cavity tapers inwardly.

6. In testing apparatus of the character described, the combination of a rotatable testing bomb and means for supporting and rotating it; said means being rotatable and having a cavity, circular in cross-section, adapted 10 receive the base of said bomb, the outer portion of said cavity flaring outwardly; a magnet at the bottom of said cavity and driving means comprising a plurality of rounded projections arranged equidistantly in a circle concentric with said magnet and said cavity and projecting from the bottom of said cavity; said bomb having 21 closed end comprising a cylindrical ferromagne-tic driving plate fitting Within said cavity in said rneans and having a plurality of holes With which said rounded projections engage and from which said projections may be rotatably disengaged.

7. Apparatus as set forth in claim 6 in which said projections are formed by studs in the bottorn of said cavity and said plate is centered in said cavity by a pin engaging said means and said plate.

References Cited by the Examiner UNITED STATES PATENTS 1136360 4/15 Parr 73-191 1,827547 10/31 Stephens 73-64 X 2475573 7/49 Smith et a1. 287-119 X 2,678,228 5/54 Gerhardt.

FOREIGN PATENTS 112,636 4/ 5 8 Russia.

RICHARD C. QUEISSER, Primary Examiner. DAVID SCHONBERG, Examz'ner. 

1. IN TESTING APPARATUS OF THE CHARACTER DESCRIBED, THE COMBINATION OF A TESTING BOMP AND COOPERATIVE SUPPORTING AND ROTATING MEANS THEREFOR; SAID MEANS BEING ROTTABLE AND HAVING A CYLINDRICAL CAVITY, A MAGNET AT THE BOTTOM OF SAID CAVITY AND DRIVING MEANS AT THE BOTTOM OF SAID CAVITY AROUND SAID MAGNET; SAID BOMB HAVING A FERROMAGNETIC DRIVING THE PLATE FITTING WITHIN SAID CAVITY, SAID PLATE HAVING MEANS ENGAGED BY SAID DRIVING MEANS FOR ROTATING SAID BOMB AND BEING ROTATABLY DISENGAGEABLE FROM SAID DRIVING MEANS. 